Expense Ratio: Lower expense ratios mean more of the fund's returns go directly to investors, positively impacting the price.

Market Performance: The overall performance of the S&P 500 index, which GSXPX tracks, is a primary driver. Bull markets lift the price, while bear markets lower it.

Fund Flows: Large inflows of cash into the fund can temporarily increase demand and potentially price, while outflows can decrease it.

Dividend Yield: Dividends paid by the underlying companies in the S&P 500 contribute to the fund's total return and influence its price.

Management Strategy: The fund's effectiveness in tracking the S&P 500 impacts its performance and, consequently, its price.

Economic Conditions: Economic indicators like GDP growth, inflation, and interest rates affect company earnings and investor sentiment, impacting the S&P 500 and GSXPX.

Investor Sentiment: Overall investor optimism or pessimism towards the stock market influences demand for funds like GSXPX.

Trading Volume: Higher trading volume can lead to price volatility, both positive and negative.

Rebalancing: When the underlying index rebalances, GSXPX needs to adjust its holdings, which can have a minor impact on price.